A vehicle brake device includes a hydraulic pressure generating device, a valve device, a pump and an accumulation section forming an accumulation chamber connected to a fluid passage between the valve device and the hydraulic pressure generating device or to a master chamber. A dead band is set in which the change of force of the magnitude corresponding to the hydraulic pressure in the master chamber does not substantially act on a brake operating member. A characteristic representing the relation between the pressure and the brake fluid quantity in the accumulation chamber is set based on a characteristic representing the relation between the pressure and the brake fluid quantity in a wheel cylinder and the dead band so that, when brake fluid is flowing into and from the accumulation chamber, a force of the magnitude corresponding to the master chamber hydraulic pressure does not act on the brake operating member.

A method for determining a likely internal pressure for a master brake cylinder including: estimating/measuring a displacement path(s) of a brake input element configured on a master cylinder from initial position thereof; estimating/measuring a first hydraulic fluid volumetric flow rate of a hydraulic fluid of the braking system out of or into a first pressure chamber of the master cylinder, and of a second hydraulic fluid volumetric flow rate of the hydraulic fluid out of or into a second pressure chamber of the master cylinder; and determining the likely internal pressure for a master cylinder considering the estimated/measured displacement path(s), the estimated and/or measured first hydraulic fluid volumetric flow rate, and the estimated and/or measured second hydraulic fluid volumetric flow rate. Also described is a device for determining a likely internal pressure for a master brake cylinder, and an electromechanical brake booster, ESP control, and vehicle braking system.

Disclosed is a braking device in which all multiple ports (for example, input ports (15c, 15d) and output ports (15a, 15b)) provided on a front surface portion (30) of a base (10) of a master cylinder (1), connector connection ports (23a, 24a) of connectors (23, 24) that electrically conducts an electrical part accommodated in a housing (20), and a pipe connection port (3c) to which a hose is connected of a reservoir (3) are arranged toward front of a vehicle when a starting device (A1) is assembled in the vehicle.

A brake control device includes a pilot-type pressure-increasing device. A pilot unit of the pressure-increasing device is connected to a power hydraulic pressure generating device via a pilot input passage. A linear control valve that is also used for adjusting a hydraulic pressure of a wheel cylinder is provided on the pilot input passage. A brake ECU checks whether the pressure-increasing device is normally activated or not based on a hydraulic pressure outputted from the pressure-increasing device when the linear control valve is energized for an activation check. Thus, the brake ECU can perform the activation check of the pressure-increasing device without requiring a driver's operation on a brake pedal.

A vehicle braking device includes: a stroke simulator for generating a hydraulic pressure corresponding to a brake operation in a hydraulic chamber, the stroke simulator having a cylinder part and a piston part for sliding through the inside of the cylinder part in conjunction with a brake operation of a brake pedal; a booster mechanism having an input part directly pressed by the piston part or pressed by a spring interposed between the input part and the piston part in conjunction with the sliding of the piston part, and thereby moved in sliding fashion through the inside of the cylinder, and a hydraulic pressure generating part for generating a first hydraulic pressure corresponding to the movement of the input part based on the hydraulic pressure of an accumulator; and a wheel cylinder for applying a braking force to a vehicle wheel on the basis of the first hydraulic pressure.

A hydraulic braking system includes: a stroke simulator; a pump configured to suck and discharge working fluid; a hydraulic brake including a brake cylinder connected to the pump; a suction mechanism including a reservoir, a suction portion of the pump, and a suction passage connecting between the reservoir and the suction portion of the pump; a first simulator passage connecting between the stroke simulator and the suction mechanism at a first connecting portion of the suction mechanism; a second simulator passage connecting between the stroke simulator and the suction mechanism in parallel with the first simulator passage at a second connecting portion of the suction mechanism, the second connecting portion being farther from the suction portion of the pump than the first connecting portion; and a flow restricting device provided on the second simulator passage.

The braking device for a vehicle includes a judging portion which judges whether the input piston and the output piston are in contact with or separated from each other and a control portion which outputs the control signal to the pilot pressure generating device so that the hydraulic pressure detected by the hydraulic pressure detecting device becomes a target value corresponding to a vehicle state, when judged that the input piston is not in contact with the output piston and outputs another control signal to the pilot pressure generating device, by which the pilot pressure becomes higher than the pilot pressure generated under a same vehicle state to a vehicle state in a case that the control signal is outputted when the judging portion judges that the input piston is not in contact with the output piston, when judged that the input piston is in contact with the output piston.

An electro-hydraulic brake system includes a master cylinder block in communication with a reservoir tank containing a brake fluid. A protrusion extends from the master cylinder block to a terminal end. The master cylinder block defines a channel extending along a center axis into the protrusion. A pressure supply unit includes a housing defining a chamber and is in communication with the reservoir tank. A displacement piston, slidably disposed in the channel, extends between a primary end located in the chamber and a secondary end located in the channel. An actuator is disposed in the chamber, rotatably coupled to the displacement piston, for axial movement along the center axis. A first anti-rotational member is disposed in the channel, coupled to the terminal end, for engaging the secondary end to prevent rotation and translate rotational movement of the actuator into the axial movement.

In an electric automobile traveling by driving a rear wheel with an electric motor mounted on a vehicle body rear part, a load distributed to the rear wheel is larger than a load distributed to a front wheel by an amount corresponding to a weight of the electric motor. Therefore, it is desirable that a braking force distribution amount to the rear wheel be larger than that to the front wheel. Without providing a proportional pressure reducing valve changing a ratio of braking force distributed between the front and rear wheels, it is possible, by supplying a same brake fluid pressure from a master cylinder to front and rear wheel brake calipers and carrying out regenerative braking in the rear wheel, to make the braking force distribution amount to the rear wheel larger than that to the front wheel.

An actuation system, in particular for a vehicle brake, may include an actuating device, such as a brake pedal, at least one first pressure source, e.g., a piston-cylinder unit (master cylinder), which can be actuated in particular by means of the actuating device and a second pressure source, in particular a piston-cylinder unit, with an electro-mechanical drive. The pressure sources may each be connected to at least one brake circuit via a hydraulic line, in order to supply the brake circuit with pressurising medium and to pressurise the vehicle brake. There may further be a valve device for regulating the brake pressure. It is planned that during forward and return stroke at least one brake circuit can be fed controlled pressurising medium by way of the second pressure source.